Several putative anti-cancer molecular targets associated with the Insulin like growth factor (IGF) signally pathway have been reported including the IGF-1 receptor (IGF-1R) and some of its defined and less defined binding partners. To date we have characterized the decrease in steady state mRNA levels mediated by synthetic siRNAs corresponding to 35 genes associated directly with or down stream of IGF-1R and its related receptors. RNA analysis was used to characterize all of the RNAi effectors, with quantitative Western blot analysis used to analyze the decrease in protein levels of some of the target proteins. In all cases at least one synthetic siRNA was identified that reduced steady-state mRNA levels of the corresponding gene significantly, and where studied this was matched with a significant decrease in protein levels that was sustained at least 96 hours. To investigate the functional consequence of the knockdown of some of the genes associated with the IGF pathway we have investigated the effect of RNAi against some of the pathway members in 2D and 3D cell culture. To date the knockdown of most genes show only a minimal effect on cell viability but a substantial effect on cell growth in 3D has been observed. We are now initiating a collaborative effort with MTP and MTDP to applying these characterized RNAi resources in additional functional assays and model systems